I don't know very much about bottles, except that the first equipment for mass-producing bottles inexpensively became available in 1903. That, however, does not mean there were no molded bottles before 1903, but before that year any bottle, regardless of how it was made, would have been pretty expensive. What does that tell you? Only, and even this might be a stretch, that it wouldn't make much sense to put cheap, crappy whiskey into an expensive bottle, so anything sold in the bottle before 1903 probably was pretty good.

Just wanted to add to this old post, the 3 pre-prohibition bottles in the original post are very rare and very collectible. I wouldn't be surprised if the 3 bottles were appraised at $1,500 each, and they could even sell for more than that at auction.